Muller-agitator



a 24, A. c; CHRISTENSEN ET AL MULLER-AGITATOR 2 Sheets-Sheet 1 Filed June 22, 1959 March 24, 1942.

A. C. CHRISTENSEN ET AL I MULLER-AGITATOR Filed June 22, 1959 2 Sheets-Sheet 2 //v l/E/VTORS flu-m1) G, Cnmsmvssu, B Y BHRNEY CAST0R. T-SMJLL. fro/wars Patented Mar. 24, 1942 MULLER-AGITATOR Alfred C. Christensen and Barney Castor, Chicago, Ill., assignors to Herbert S. Simpson,

Chicago, 111.

Application June 22, 1939, Serial No. 280,604

2 Claims.

This invention relates to a muller-agitator which is particularly adapted to the preparation of ceramic and chemical mixtures, and may be used for the preparation of foundry sand, battery paste or the like. In general, it may be employed for the mulling and mixing of dry materials with one another, such as sand with clay, or the mixing of dry materials with liquids, such as in the preparation of battery paste from lead oxides and sulphuric acid.

The principal object of the invention is to provide a muller-agitator which is adapted to both mull and intensively agitate chemical or ceramic materials. The device comprises a muller pan, a muller wheel revolving therein, and an agitator which is revolved in a manner similar to the muller wheel but which is rotated at relatively high speed as it is revolved. The result is that the material being treated is mulled and mixed with great effectiveness.

Another object is to provide a muller-agitator comprising a muller wheel and a revolved agitator operating in the muller pan with the muller wheel and which is positively rotated about its own axis as it is revolved.

Another object is to provide a device of the type just described wherein the agitator is carried by the same cross head and is driven by the same central driving shaft as the muller wheel.

Still another object is to positively rotate the agitator of a muller-agitator by stationary means drivingly connected to the agitator so that as the agitator is revolved in the muller pan, it is rotated by its driving connection.

Still other objects will more fully hereinafter appear.

Referring to the accompanying drawings:

Figure 1 is a plan view of one form of agitator embodying the principles of the present invention. 1

Figure 2 is a vertical sectional View, taken through the muller-agitator of Figure 1, showing the parts within the muller pan in elevation.

Figure 3 is a detailed sectional view of the upper portion of the central driving shaft showing the manner in which the stationary sprocket is journaled about the central driving shaft.

Figure 4 is a plan view of a modified form of the invention.

Figure 5 is a schematic view of yet another modified form of the invention.

Referring to the drawings in detail, and first to the embodiment of Figures 1 to 3, reference numeral I designates generally the muller pan which has a supporting bottom casting 2, provided with a circular wear-resisting bottom plate 3, and side wall 4.

Rigidly supported below the muller panl is a horizontal drive shaft H which is connected to any suitable source of power, and which drives central driving shaft l2 through the intermediary of intermeshing gears l3 and I4. Central driving shaft I2 projects upwardly through the center of the muller pan, upwardy through a stationary turret 5 which is provided in the center of wear plate 3 and which is concentric with central driving shaft l2. Keyed or splined to central driving shaft l2 above turret 5 is a cross head designated generally as l5, to which the muller wheel 2| and the agitator 3| are attached so as tobe revolved about the central axis of the muller as central driving shaft l2 rotates. Cross head i5 is provided with a downwardly extending skirt [6 which extends downwardy around the upper portion of turret 5 so as to keep material being mixed from obtaining access to the interior of turret 5 or to the bearings of central driving shaft l2.

Muller wheel 21 is revolved about the central axis of the muller pan by reason of its connection to cross head [5 by a vertically swingable arm 22. Arm 22 is so arranged that the muller wheel 2 is supported a short distance above the bottom of the muller pan as indicated in Figure 2. This clearance between muller wheel 2| and the upper surface of wear-resisting plate 3 is provided in such a way that muller wheel 2| may exert a maximum mulling action and a minimum grinding action, thereby efiecting a more rapid coating of one ingredient of the mix with another ingredient and in the production of a superior product. Muller wheel 2| is rotated on its own axis as it is revolved in the muller pan. This is accomplished by the provision of a shaft 23 fixedly mounted in the end of arm 22 and about which muller wheel 2| is journaled. Muller wheel 2| is so disposed that its axis is carried somewhat behind the central axis of the central driv ing shaft I2, as is clearly shown in Figure 1 of the drawings. As muller wheel 2| is revolved, it is free to rise upwardly in order to pass over the material being mixed or mulled, but is prevented from coming into contact with the bottom of the muller pan by reason of its suspension thereabove, even when no material is in the muller pan.

Substantially diametrically opposed'to muller wheel 2| is the agitator assembly 3| carried on the opposite end of cross head l5. The central axis of agitator assembly 3| is carried at approximately the same distance from the center of driving shaft I2 as the central longitudinal axis of muller wheel 2|, so that muller wheel 2| is revolved within the path of agitator assembly 3|. Agitator assembly 3| comprises a vertical shaft 32 which is journaled in a casting I! mounted on the end of cross head I5. Any suitable bearings may be provided in bearing housings 33 which are mounted on each side of casting H, in order to rotatably guide shaft 32 and to transmit any upward or downward thrust imposed thereupon to the bottom supporting casting 2 through cross head I and central shaft I2. As shown, a loadsupporting washer 34 is fixedly attached to shaft 32 above the upper bearing housing 33 and serves to transmit the weight of agitator assembly to casting II; a similar washer 35, similarly fixedly attached to shaft 32 bears against the lower bearing housing 33 and transmits any upward thrust thereto.

The agitator itself comprises a horizontal flat member 36 which is fixedly attached to shaft 32 between washer 35 and a collar 31, so that member 36 is in driving engagement with shaft 32. Fixedly attached at their upper ends to member 36 are vertical blades 38 which extend downwardly to a point just above the upper surface of wear plate 3. These blades are preferably disposed in the manner shown in the drawings, an equal number being disposed on each side of the central axis of shaft 32, and the opposite blades being equally disposed from said central axis. However, it is to be understood that an unsymmetrical arrangement may be employed if desired.

Means is provided for rotating the agitator shaft 32 and the agitator assembly 3| as it revolves in the muller pan. This means may take the form shown in Figures 1 to 3, wherein a sprocket 4| is stationarily supported concentrically with the central driving shaft I2 by means of an arm 42 and spacing bolts 43. Arm 42 is fixedly attached to the upper portion of one side of the muller pan, as indicated at the right hand side of Figures 1 and 2. A sprocket 44 is fixedly attached at the upper end of shaft 32 and a sprocket chain 45 encircles sprockets 4| and 44. The result is that as sprocket 44 revolves about the central axis of the muller, it is rotated in the direction indicated by the arrows B of Figure 1.

Stationary sprocket 4| is journaled about an upwardly projecting portion I8 of shaft I2. A collar 45, fixedly attached to sprocket 4|, rests in supporting engagement upon a thrust washer 41 which is free to rotate relative to a nut 48 which is fixedly engaged with shaft I2. Thus the sprocket 4| is journaled with respect to shaft I2 sothat shaft I2 is free to rotate therein and supports the weight of sprocket 4|.

In the modification shown in Figure 4, the agitating assembly 3| is rotated in the same direction as that described above by means of a stationary driving rim 49 concentrically supported from the upper edge of side wall 4. A friction gear 50, fixedly attached to shaft 32, frictionally engages stationary driving rim 49 and causes the agitator assembly 3| to be rotated as it is revolved. Preferably, the agitator assembly is yieldingly pressed radially outwardly so that a good driving contact between gear 50 and rim 49 is obtained. This may be accomplished by mounting the agitator assembly on a casting IIa which is provided with slots slidingly' engaging pins IIb fixedly mounted on casting I1 and by providing a compression spring IIc yieldingly interposed between castings I1 and I'Ia.

A still further modification is shown in Figure 5 wherein a stationary toothed or friction gear 5| is journaled about the central driving shaft in a manner similar to that described in connection with sprocket 4|. A friction or toothed gear 52 is fixedly attached to the agitator shaft 32 and is driven from gear 5| through an idler gear 53 which is carried upon casting II. Thus the agitator assembly is driven in the same direction as that described above. Gears 5|, 52 and 53 may be either friction gears or toothed gears.

In order to keep dust and material being mixed from entering the journal of sprocket 4|, it is preferred to mount a dust cap 54 on the extreme upper end of projecting shaft I8.

A scraper 6|, carried by an arm 62 from cross head I5, scrapes the side wall 4 of the muller pan and the outer portion of the bottom 3, and delivers the scraped material into the path of muller wheel 2| and agitator 3|. This scraper blade is preferably of a height at its extreme outward portion such that it scrapes the side wall 4 entirely free of material adhering thereto. Scraper blad 6| is preferably adjustable vertically, angularly and radially in any suitable manner. A plow 63, carried by an arm 64, fixedly attached to cross head I5, scrapes the turret 5 and the inner or central bottom portion of the muller pan, discharging the scraped material outwardly into the paths of the agitator assembly 3| and scraper blade 6|. As a result of the disposition of the scraper 6| and plow 63, the mixing and mulling action is speeded up and is more effective, the material being continually moved from the path of the muller wheel inwardly towards the turret and outwardly towards the side walls and being continually returned into the path of the muller wheel. Thus, the agitator assembly 3| and the muller wheel 2| are made to act upon the material being treated in a more rapid and more efficient manner and the cooperation between them is enhanced.

As will be understood, the central driving shaft is rotated in such a direction that the parts in the muller pan revolve in the direction indicated by arrows A'on Figure 1. As the parts so revolve, agitator assembly3| rotates on its own axis in a direction indicated by the arrows B of Figure 1. If desired, the agitator assembly may be positively driven in the opposite direction although when it is rotated in an opposite direction, the effectiveness of the mixing is considerably reduced. As will be further understood from the above description, agitator assembly 3| is rotated a plurality of times, say four or more, per revolution of the same in the muller pan. While the inventive thought may be carried out by positively rotating the agitator assembly only once per revolution in the muller pan, it is preferred to have it rotated more than once per revolution since such higher rotation greatly enhances the effectiveness of the mulling and mixing.

We wish it to be understood that we desire to include within our invention such modifications thereof as fall within the scope of the appended claims and the invention.

Having thus fully described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A muller-agitator comprising a muller pan, a cross-head in said pan, means for rotating said cross-head in said pan about its central axis which substantially coincides with the central axis of said pan, a muller wheel adapted to rotate about its own horizontal axis and revolved by said cross-head in an orbital path about said central axis, said muller wheel being carried at one end of said cross-head, an agitator assembly carried by the other end of said cross-head having its axis of rotation intermediate the side of the pan and the center thereof and revolved thereby in an orbital path which extends on both sides of said muller wheel, said agitator assembly comprising a vertical shaft journaled in said cross head, a horizontal member fixedly attached at approximately its center to said shaft, and a plurality of rectilinearly aligned spaced mixing blades fixedly carried by said horizontal member and depending downwardly therefrom towards said muller pan, there being an equal number of said blades on each side of said vertical shaft, and means for positively rotating said vertical shaft and thereby said mixing assembly as said mixing assembly is revolved by said cross-head, to produce an intensive rotary mixing action within an orbital path in advance of said mulling wheel and of greater width than said wheel.

2. A muller-agitator comprising a muller pan, a cross-head, means for rotating said cross-head about a vertical central axis of said pan, a muller wheel carried by said cross-head in a circular path about said central axis and rotating about its own horizontal axis as it is so carried, an agitator assembly carried by said cross-head and revolved thereby about said central axis in advance of but in substantially the same path as said muller wheel, said agitator assembly being rotatable about a vertical axis of rotation and comprising a supporting member passing through said last-named axis and a plurality of substantially rectangular fingers extending downwardly therefrom to a point adjacent the bottom surface of said pan, said fingers being in spaced relation along said supporting member and on both sides of said last-named axis with their flat sides substantially normal to a radius through said last-named axis, and means for rotating said agitator assembly about said lastnamed axis as said agitator assembly is revolved by rotation of said cross-head about said firstnamed axis to produce an intensive rotary mixing action in a path in advance of said muller wheel, said path encompassing the path of the muller wheel, the lower ends of said rods remaining in a substantially horizontal plane as they rotate.

ALFRED C. CHRISTENSEN. BARNEY CASTOR. 

